Objective To observe the pathomorphological changes and expressions of TNF-α, SOD1 and SOD2 in cardiac tissues of rats with abdominal aorta champing(AAC)and LPS attack.Methods Forty Wistar rats were randomly divided into four groups:sham operated group (Group S),ischemia reperfusion with AAC group(Group I /R),intraperitoneal injection of endotoxin group(Group LPS)and AAC +LPS group(Group I /R +LPS).Animals were sacrificed after 20 minutes of AAC and 8 hours of reperfusion.Cardiac tissues were observed with HE staining for pathmmorphological changes,and detection of TNF-α,SOD1 and SOD2 expressions were tested by immunohistochemistry.Results The mortality rate of Group I /R +LPS was highest.HE staining of the cardiac tissues revealed that the pathological changes of myocardial tissue were not obvious in Group S;myocardial cells were disordered and slightly swollen and red blood cell and inflammatory cells were observed in the intramuscular space of the Group LPS;these injuries were more serious in the Group I /R;the injuries of cardiac tissues were most serious in Group I /R +LPS.The results of immunohistochemical staining revealed that TNF-αexpression level of cardiac tissue increased as followings:Group S,Group LPS,Group I /R and Group I /R +LPS.Significant differences were observed among groups,except for the difference between Group LPS and Group I /R.The expression level of SOD1 decreased as followings:Group S,Group LPS,Group I /R and Group I /R +LPS. Significant differences were observed among groups,except for the difference between Group I /R and Group I /R +LPS.The expression level of SOD2 decreased as followings:Group S,Group LPS,Group I /R +LPS and Group I /R.Significant differences were observed among groups,except for the differences between Group LPS and I /R and Group I /R +LPS.Conclusion The mortality in rats with sepsis after abdominal aorta clamping is high.Obvious myocardial morphological changes and injuries exist either in ischemia reperfusion or sepsis state.At the same time,the expression of TNF-αis up-regulated while SOD1 and SOD2 are down-regulated.